Little low earth orbit (LLEO) satellite systems provide low cost modems that communicate with satellites. These modems can be attached to customer assets such as trucks, trailers, train cars, shipping containers, etc. to give the Customer the ability to track and monitor assets across the world. The modems typically communicate with the LLEOs via an antenna, which transmits and, when required, receives information from the satellite. Conventional designs for antennas for this application include only electrical antennas, which have relatively low radiation efficiencies and are relatively large in size in comparison with other some other types of antennas.
Modems for LLEO applications are generally installed within a truck or a truck-drawn trailer to protect the modem from damage, theft, and vandalism. The antenna, on the other hand, must be installed on the outside of the trailer to have visibility to the sky, but there is little clearance and little available space on the outside of the trailer, and most types of smaller antennas suffer from narrow bandwidths and low efficiency when mounted relatively close to a ground plane, which is the case for LLEO antennas mounted on trailers. Additional problems encountered for LLEO communication applications include the low elevation coverage required, the dual-frequency nature of the application, the desired non-intrusive features of the application, and cost considerations, to name but a few.